The present invention concerns a control device and method for the emergency opening of an aircraft evacuation door. It also concerns an aircraft emergency evacuation device equipped with such an opening control. Evacuation door is taken to mean an aircraft door intended as an exit door for the occupants of an aircraft in case of an incident or accident. An evacuation door can also be used, under normal use conditions, for embarkation and disembarkation of passengers and/or the crew members of the aircraft.
The invention can be applied to different types of aircraft, including civil or military, and in particular to passenger transport airplanes.
Aircraft entries/exits are typically delimited by a frame, connected to the fuselage, which receives a door linked to it by a hinge. The hinge defines the door""s travel as it is displaced between open and closed positions. The hinge also allows control of the door""s orientation whilst it is being displaced.
Entries/exits are also equipped with means for locking the door to the frame. The locking means, designed to ensure the door""s closed position, are usually handled manually by the crew or by the airport""s ground personnel.
Lastly, the door and the frame are provided with stops which come into contact during closing. Pressurisation inside the aircraft assists in maintaining contact between the stops and support surfaces to which they are coupled.
Aircraft entries/exits can be used as safety exits for an emergency evacuation. For this application they are equipped with evacuation equipment such as inflatable slides, for example. The slides can be stored in compartments built into the fuselage or the aircraft""s wing It is nevertheless more usual to arrange for a compartment for the slides directly in the entry/exit doors able to be used in the event of emergency evacuation.
When the door is closed, following passenger embarkation, the personnel on board arm a system which mechanically connects the slide, stowed in the door, to the door threshold, that is to the fixed frame.
For normal opening of the door, the system mechanically connecting the slide to the door frame is disarmed allowing the door to be opened without deployment of the slide.
On the other hand, in the case where door opening occurs during an emergency evacuation procedure, the slide is automatically deployed outside the aircraft.
Slide deployment takes place, for example, by inflation using a means of inflation designed for this purpose.
Certification authority regulations stipulate that total evacuation of an aircraft must be carried out within 90 seconds, with half the doors and safety exits operational. This time interval commences when an evacuation signal (illuminated panel, sound signal) is emitted, and terminates when all passengers and crew have reached the ground. It thus encompasses the opening of the doors, slide inflation, evacuation of passengers, the crew verifying that all passengers have in fact left the aircraft and crew evacuation. These different stages are all the more difficult to implement in the allotted time, considering the passengers"" inevitable hesitation at the top of the slides and the escape route passengers must take to get to the safety exits.
Given the very short time allowed for total evacuation of passengers and crew, it is important to carry out operations not subject to human intervention in a minimum time period, that is, in particular, the opening of the door and the slide inflation. To this effect, in the event of an accident or incident, an emergency door opening device replaces the device used in a normal situation. When personnel on board unlock the door to open it, the emergency opening device automatically applies a very significant force to the door allowing it to be rapidly opened, without human intervention and overcoming the external constraints which might impede its opening. Generally, strong pressure is supplied in a cylinder which, by means of a piston, causes the door to be suddenly opened.
At the same time, the action of unlocking the door initiates the slide deployment and inflation. Typically, the duration of these operations (opening of the door and deployment-inflation of the slide) should not exceed 10 seconds.
Aeronautical manufacturers seek to gain time in these automatic operations of opening of the door and deployment-inflation of the slide. These operations are effectively the only ones it is possible to optimize. An ongoing aim is thus to increase the speed of opening of the door and of deployment/inflation of the slide.
A safety issue however arises when the time taken for opening the door is insufficient to ensure complete deployment of the slide.
Document EP-0 741 073 is cited as an illustration of the technological background. It describes a damping device for opening and closing of an onboard access door. The document only applies, however, to opening and closing of the door under normal conditions of use, that is for embarkation and disembarkation of passengers. The described device stops an unexpected strong pressure exerted on the door (for example a gust of wind) throwing the door against the fuselage (entailing risk of shock and damage to the fuselage or to one of the door""s own mechanisms) or a crew member""s limb (for example, an arm stuck in the door frame). The device described in the abovementioned document has thus as its sole objective to respond to an untimely external prompting capable of modifying the normal operating conditions of the door.
The present invention aims to propose a command device and method for emergency opening of an aircraft door, as well as an emergency evacuation device which does not have the limitations mentioned above.
One objective is in particular to allow emergency opening of entry/exit doors which is particularly rapid.
Another objective is to avoid complete opening of the door before deployment of an evacuation equipment associated with the entry/exit under consideration
One objective, finally, is not to delay the opening of the door until complete deployment of the evacuation equipment.
To attain these objectives, the invention has, more precisely, as its object, a control device for emergency opening of an aircraft door comprising:
at least one triggering mechanism for emergency opening,
at least one door actuator, and
means of power supply to the actuator responding to the triggering mechanism.
According to the invention, the device also comprises means for modification of the power delivered by the means of power supply to the actuator, to allow the door to be opened more slowly in an initial phase of opening and more rapidly in at least one subsequent opening phase. Whilst the description which follows refers to only one triggering mechanism and one actuator, it is understood the device of the invention may comprise several triggering mechanisms, manual or automatic, as well as several actuators. In the case of a number of actuators, these can work in a concomitant, successive or sequential fashion.
Whilst, in each phase, the power delivered to the actuator is sufficient to allow the door to be opened, the power delivered to the actuator is weaker in the initial phase than in the subsequent phase or phases. In the initial phase the power is provided for producing a relatively slow opening.
The slow initial opening of the door, whilst simultaneously triggering the opening of the door and the deployment of the evacuation equipment, permits the full opening of the door to be delayed, thus allowing time for the evacuation equipment""s deployment. The slow phase of door opening is termed the initial phase insofar as the door is not completely opened at the end of this phase. This feature prevents an agitated passenger from climbing out of the aircraft before complete deployment of the evacuation equipment.
During the subsequent phase or phases of door opening, a greater power is supplied to the actuator so as to proceed with and rapidly complete the opening of the door.
In one particular embodiment of the control device, it can comprise a time delay sequencer to control delivery of a first power to the actuator during the initial phase and of a second power greater than the first power in the final phase.
The time delay sequencer can be, for example, an electric sequencer. It can also comprise a trigger spring capable of being released by the triggering mechanism and coupled to a shock absorber. The sequencer is connected to the means for modification of the power delivered to the actuator.
In variations not described in detail here, the opening phases can also be controlled by the degree of deployment of the passenger evacuation equipment.
The means of power supply can be, for example, electric, hydraulic or pneumatic. They are then linked to actuators in the form of electric, hydraulic or pneumatic cylinders.
In one advantageous implementation of the invention, described hereafter, the means of power supply are pneumatic and, more precisely, of pressurized gas.
They comprise, for example, a first and second source of pressurized gas, the first source of pressurized gas being at a lower pressure than the second source of pressurized gas. The means for modification of the power delivered to the actuator comprises a distributor to successively connect the actuator to the first then the second source of pressurized gas. The sources of pressurized gas can comprise reservoirs of compressed air or nitrogen.
Supply of the first source of pressurized gas to the actuator corresponds to the initial slow opening phase, whilst supply of the second source of pressurized gas to the actuator, corresponds, for example, to a second phase of rapid and complete opening of the door.
According to an alternative embodiment of the device, the means of power can also comprise a single source of pressurized gas. In this case, the means for modification of the power delivered to the actuator comprise a regulating valve for regulating a gas flow between the source of pressurized gas and the actuator.
The invention also concerns an aircraft emergency evacuation device comprising:
an aircraft evacuation door
at least one item of passenger evacuation equipment capable of being deployed close to the door, and
a control device for emergency opening of the door, such as described above.
Evacuation equipment is taken to mean all equipment capable of being deployed in an emergency to facilitate the evacuation of passengers and crew. In particular the evacuation equipment can include one or several inflatable slides and/or equipment able to be used as life rafts.
Advantageously, the emergency opening triggering mechanism may be coupled to means of deployment of the passenger evacuation equipment.
Lastly, the invention concerns an automatic emergency opening method for an aircraft door. According to the method, the door receives a first actuation in an initial phase of opening and a second actuation, greater than the first, in a subsequent phase of opening of the door.
Whilst deployment of the evacuation equipment can still be achieved during a phase of opening subsequent to the initial phase, the duration of the initial phase is preferably set so as to be greater than or equal to the duration of deployment of the evacuation equipment For example, the duration of the initial phase of the door opening and slide deployment may be in the order of 6 seconds and that of a subsequent opening phase may be 4 seconds.
Other characteristics and advantages of the invention will emerge from the following description, in reference to the figures of the accompanying drawings. This description is given purely by way of illustration and is not restrictive.